Question

what is the general reaction scheme for a double replacement reaction?
ab + cd --> cb + ad
a + cd --> c + ad
a + b --> ab
cₓhᵧ + o₂ --> co₂ + h₂o
ab --> a + b

Explanation:

A double replacement reaction involves the exchange of ions between two compounds. The general form is when two compounds (AB and CD) react, and their cations and anions swap to form two new compounds (CB and AD, or AD and CB). So the reaction scheme \( AB + CD
ightarrow CB + AD \) (or \( AB + CD
ightarrow AD + CB \)) fits this. The other options: \( A + CD
ightarrow C + AD \) is single replacement, \( A + B
ightarrow AB \) is synthesis, \( C_xH_y + O_2
ightarrow CO_2 + H_2O \) is combustion, and \( AB
ightarrow A + B \) is decomposition.

Answer:

A. \( AB + CD
ightarrow CB + AD \)